Answer:

Step-by-step explanation:
The rate of change in the temperature T of coffee at time t is written as
(remember derivatives are used to express rates of change, and in our case the rate of change of the temperature T). The difference between the temperature M of the air at time t, and the temperature T of the coffee at time t can be expressed as 
Saying that the rate of change in the temperature T is proportional to the difference between M and T is just a way of saying that the rate of change in the temperature T is equal to the difference between M and T, multiplied by some constant k (whose value we don't know, but still that's what it means).
Therefore we get

Since DC = 12, then EF also = 12.
Both AD and BC are indicated to be the same .
So AE = (24 - 12) / 2 = 12/2 = 6
Now you have a right triangle with height DE = 8 and base AE = 6
Using the Pythagorean Theorem we can now find AD:
AD = √(8^2 + 6^2)
AD = √(64 + 36)
AD =√100
AD = 10
The original price would have been $312.5
The answer is : 20x^50
Hope this helps!
The number -5 would go to the left of a number scale. Typically because all negatives move to the left of zero on the number scale.